JPH09208689A - Continuous polymerization of active anionic lactam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for continuous polymn. of an active anionic lactam according to which a const.-quality homogeneous polylactam can be obtd. with excellent efficiency and reproducibility through a rapid and homogeneous reaction of the lactam.

SOLUTION: According to the process for continuous polymn. of an active anionic lactam in an inert atmosphere, a lactam for anionic lactam polymn., a catalyst, and an activator are fed under anhydrous conditions to a mixing and conveying unit capable of heating and continuous operation, wherein the lactam is heated to an operating temp. while continuously mixing the same to effect at least partial polymn., and the resulting melt is either shaped in a mold or extruded in the form of a strand. Addn. of the activator and the catalyst to the anhydrous lactam melt is effected by continuous addn. of a liq. system containing both of the activator and the catalyst.

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous polymerization method of active anionic lactam and a shaped polyamide b obtainable by this continuous polymerization method.
odies).

[0002]

2. Description of the Related Art According to the related prior art, polylactams and polyamides are mainly used in accordance with the so-called hydrolytic polymerization process, with the amount of about 200-200.
Produced from molten lactam at a temperature of 320 ° C., the pressurization step by addition of water to open the lactam ring often corresponds to the slower first step of the reaction in this process. This reaction product, preferably the particulate material, is converted in a subsequent step into a useful product, for example by injection molding or extrusion.

For example, metal lactam
A strong base capable of inducing the formation of ate) can also cause the conversion of the lactam to a polyamide. This corresponding polymerization reaction proceeded slowly, thus superseding the active anionic lactam polymerization, which can accelerate the reaction very much and lower the polymerization temperature below the melting point of the polymer. In this method, the catalyst and activator are added separately to the molten lactam.

By convention, the catalyst is usually present as a solid, for example an alkali or alkaline earth lactamate. Also, many activators (or cocatalysts), such as carbodiimides and blocked isocyanates, are solid. The disadvantage of free isocyanates, which are mostly liquid, is their high toxicity.

For the anionic lactam polymerization and the active anionic lactam polymerization, see, for example, Plastic Manual, Volume 6, Polyamide, C. Hans (C. Hans).
er), the publisher, Munich.

The active anionic lactam polymerization is generally carried out, preferably by the so-called 2-tank process, in order to produce so-called castings or semi-finished products of large size, for example profiles.

Therein, equal volumes of lactam melts containing catalyst or cocatalyst, respectively, are prepared, combined and vigorously mixed. This initiates the polymerization and immediately afterwards the melt can be processed into a finished product, for example by the so-called monomer casting method.

In this process, it is necessary to pay attention to the following: -the lactam melt is free of water and oxygen; -the mixing and processing steps are carried out in an inert gas; -processing Processing the active melt very quickly as time is limited.

So-called liquid catalyst systems have been developed to facilitate the rapid and uniform distribution of catalysts such as magnesium or sodium lactamate in the lactam melt.

In German Patent Publication DE-2230732 C3, a catalyst in solid form into an activator-containing lactam melt,
For example, the problem of adding metal lactamates is mentioned. A poorly reproducible, malformed, heterogeneous polymer is obtained.

In order to solve this problem, German Patent Publication DE-A-1495132 describes an alkali lactamate which is a liquid at 90 ° C. and further contains 0.3 to 5.0% by weight of a low volatile amine. A lactam solution of is proposed.

US Pat. No. 3,575,938 describes N, N
Dissolving a metal lactamate catalyst in a disubstituted urea, especially N-methylpyrrolidone is disclosed. The improved addition and distribution of the catalyst solution to the active lactam melt also allows the production of mineral-filled products.

German patent publication DE-223 already mentioned
According to the teachings of 0732 C3, the formation of crusts that appear more rapidly and interfere with processing by the catalyst solution prepared from the alkali lactamate in 2-pyrrolidone,
It is necessary to prevent this by adding higher alcohols.

European Patent Publication EP 0438762 B1 discloses a catalyst solution which is very stable even when stored at low temperatures, which leads to a rapid reaction and leads to polyamides containing relatively small amounts of extractable contents. To do. They consist of lactams, 2-pyrrolidone and further additives such as certain glycols, hydrocarbons and selective amines which influence the properties of the polymer.

However, the cited prior art requires that the activator and catalyst solutions be added separately.

Therein, the preferred method of proceeding is to first prepare a homogeneous anhydrous lactam melt solution of the activator and, if desired, further additives to initiate the polymerization reaction. In a further processing step, the catalyst, preferably dissolved in lactam, is added and distributed homogeneously in the melt.

In this case, the solution is required to be free of oxygen and water: mixing and processing in the reaction vessel must be carried out in dry inert gas.

Since the reaction time in the above step is sufficiently short, a promoter is required in addition to the catalyst, and therefore it is necessary to operate in accordance with an accurately determined processing method.

In the general method, about the same volume of melt is prepared containing either the catalyst or the activator dissolved therein. The melt is then mixed, which initiates the accelerated polymerization process. A disadvantage in these steps is the need to prepare two different melts in two different vessels, and catalyst-containing melts have a limited shelf life even when no activator is present. There is. After pouring them together, the melt has a sufficiently low viscosity that the pot live for processing is still limited, so that intermediate storage of the active melt is not possible, for example: Imprinting must be done immediately.

Another method involves emptying two vessels, each containing a catalyst or activator, and continuously mixing the melts in a mixing step, after which the active melts are processed.

Here again, there is the problem that the storage time of the melt is limited.

In a further method according to the prior art,
For example, according to U.S. Pat. No. 3,575,938, an activator and a selective dry additive, such as fiber, is mixed with the lactam melt and a catalyst solution is added in a subsequent step,
Distribute evenly by mixing vigorously. This addition and distribution method is facilitated if a catalyst solution can be used. However, this method still remains a multi-step method.

[0023]

DISCLOSURE OF THE INVENTION The present invention provides a continuous polymerization of an active anion lactam which is highly efficient and reproducible, and which can give a uniform quality polylactam, and the reaction of the lactam is rapid and uniform. It is intended to provide a method and thereby to simplify the processing and its application work.

[0024]

SUMMARY OF THE INVENTION The present invention is a process for feeding a lactam for anionic lactam polymerization under anhydrous conditions and a catalyst and activator to a continuously heatable and continuously operating mixing and conveying device, the lactam. Heating to operating temperature with continuous mixing to at least partially polymerize, and shaping in a mold or delivering the melt as a strand, rather than cooling and pelletizing. In a continuous polymerization process of active anionic lactam under inert atmosphere, the addition of activator and catalyst to the anhydrous lactam melt is carried out by continuous addition in a liquid system containing both activator and catalyst. The present invention relates to a continuous polymerization method of an active anion lactam characterized by

The present invention also relates to the polylactam produced by the above method.

The above object is especially to use a solution which is stable on storage and liquid at room temperature and which simultaneously contains an activator and a catalyst for anionic lactam polymerization, wherein the solution contains the activator or the catalyst separately. It is achieved by a process which makes it unnecessary and thus can be carried out continuously for the active alkali lactam polymerization with a system which ensures considerable development in application, formulation and manufacturing parameters and in the shaping process. In this case, in addition to the activator / catalyst liquid system, lactam or its pure which is stable on storage, while being activated and catalyzed directly in one step before shaping by continuous addition of only one liquid system. It is particularly advantageous that only the desired melt need be obtained.

The process according to the invention comprises a lactam, preferably caprolactam and enatholactam,
And especially with laurinlactam.

While stirring the melt, the liquid system is rapidly and evenly distributed in the lactam melt, initiating the polymerization uniformly and quickly.

This represents a considerable advantage, especially for laurinlactams, which must be stored before processing at a melting point above about 160 ° C., which considerably shortens the storage time in the presence of catalysts.

In the process according to the invention, therefore, a single storage tank for the molten lactam is sufficient, which can be easily stored for long periods under an inert gas atmosphere due to the lack of catalyst or activator. You can

Because of the use of liquid systems, the continuous process of the present invention provides continuous shaping of polylactams, especially polycaprolactams and polyenantho-lactams, and especially polymeric melts of polylaurinlactams and mixtures thereof. This is possible because of the high polymerization rate of the above method.

In the process of the present invention, the liquid system to be added to the anhydrous lactam melt consists essentially of: a) a1) at least 1 as a basic component and solvent.
20 to 80 parts by weight of one N-substituted carboxylic acid amide compound, and / or a2) at least one N, N′-disubstituted urea compound (both of which may also include a heterocycle formed by their substitution) b) 5 to 30 parts by weight of at least one alkali or alkaline earth lactamate as catalyst c) 5 to 30 parts by weight of at least one compound activating anionic lactam polymerization [a), b) and c) 10
0 parts by weight or less and optionally the following d) are added] d) Components which do not influence the polymerization or only in the desired and predictable extent, components a), b) and c)
Additives and additives depending on the processing and / or use that are compatible with.

The N, N'-disubstituted urea compound a2) is CA
S80-73-9 and CAS 7226-23-5, and BASF company publication "BASF-Zwischenprodukte 1993" [BASF.
Intermediate].

N-substituted carboxylic acid amide compounds a1) and alkali and alkaline earth lactamates b) are described in US Pat. No. 3,575,938.

Preferably the activating compound c) is a blocked, especially lactam blocked isocyanate, carbodiimides, acylated lactams and reaction products with oxazolines and oxazoline derivatives, especially fatty alkyl oxazolines and isocyanates. Is. Such products are, for example,
Farben und Lacke [Paints and lacquers] 1993/11, pp.911-915.

In the process according to the invention, the pure anhydrous lactam is continuously conveyed in unmelted or molten form from the storage vessel and is a transport and melt-mixing device for continuous operation, preferably with multiple processing zones. Guided by a twin screw extruder. Thus, the lactam melt is continuously mixed and conveyed, or continuously melted first,
Either mixed and transported. In this method, the liquid system is vigorously mixed with a constant ratio of 0.5-1.
It is advantageously added to the lactam melt at 5% by weight.

In the subsequent processing area, 200 to 320 ° C.,
In particular, increasing the temperature to 240-290 ° C. accelerates the polymerization, so that the polymerization takes place within 100-200 seconds.

In a preferred embodiment, the present polymerization process includes a degassing step in which volatile components, volatile reaction byproducts and unreacted lactam from the melt are depressurized at atmospheric pressure or selectively under reduced pressure. It can be removed under vacuum or under vacuum.

In the last process step, the polymerizable melt is discharged from the above apparatus, preferably an extruder, by means of single or double nozzles, after which the polymer strands are cooled at least below their melting point and taken up as monofilaments, for example preferably Is finely crushed into cylindrical granules. They can then be subjected to further processing steps, for example by injection molding or extrusion.

In important process variants, the polymerisable melt is conveyed directly to the shaping tool and is taken up by known methods according to the prior art, in particular as monofilaments, tubes or profiled elements. , Provided for direct use of it.

In a further process variant, further process- and / or use-related additives are added to the active melt. They can also be added directly to the lactam to be conveyed, or as a masterbatch or in a later processing step.

The following are preferably used as additives and additives d): conventionally known processing aids,
Plasticizers, light and heat stabilizers, antioxidants, certain flame retardants, optical brighteners, pigments, dyes, tracers and aromatic hydrocarbons.

In the present invention, the active catalyst-containing melt stream is obtained by balancing proportional amounts of liquid system, temperature control and residence time in the extruder, at least it is fed directly to the shaping mould. To the extent that can be done, the polymerization can be sufficient while optionally including processing steps for the addition of additional components to the system and / or degassing of the melt, and further polymerization there if desired.

The advantages of the process of the invention are: -The active anionic lactam polymerization can be carried out efficiently and reproducibly-The polymerization can be carried out continuously, preferably in a twin-screw extruder; -By using a liquid system that simultaneously contains an activator and a catalyst, it is possible to obtain a uniform quality polylactam of constant quality; -the reaction of the lactam is rapid and uniform, 100-
Mostly after 200 seconds; this method can be directly combined with a continuous shaping step; the technical outlay required in this polymerization method is obviously related to hydrolysis polymerization The thermal stress of the polymer is significantly reduced.

The method of the present invention can be developed and used in a variety of ways. In order to achieve certain good polymer properties, it is advantageous to work in an inert atmosphere, in an inert gas or in an inert liquid, in the absence of water.
This also applies to degassing domes and die areas, with particular attention in connection with lactam and additive feeding and by-products.

Suitable twin-screw extruders include, for example, those of the type identified as the Werner und Pfleiderer company, the Stuttgart (FRG) ZSK machine. Further processing operations can be advantageously performed.

In a preferred processing variant, the additives are added to the melt of the invention, distributed therein or, if desired, after the polymerization step has been rapidly carried out by the process of the invention. Can react with the body. For example,
Continuous addition of toughening or polymer plasticizers, as well as flame retardants, inorganic fillers, fibers such as glass fibers, carbon fibers and other polymers acting as aramid fibers to the fresh polymerizable melt stream is Twin-screw side extruder
It is possible with an extruder).

Further additives and additives having a special function, eg stabilizing effect, are alcohols, phenols, in particular sterically hindered phenols, aliphatic and aromatic amines, silanes, tracers, complexing agents, It is selected from the group consisting of antistatic agents, carboxylic acid amides and carboxylic acid esters, and tensides.

They can be added to the melt stream together with the plasticizer as part of the liquid system, or they can be added separately, for example directly to the initial lactam melt.

As a further processing step, in another preferred variant, the subsequent thermal treatment of the polylactam is carried out, for example, just below the melting point of the polylactam, advantageously under a dry inert gas atmosphere. According to the prior art, it is then possible to improve the properties of the polymer, in particular to reduce the residual lactam ratio and increase the viscosity.

Highest temperature, 2 for PA6
20 ° C and 170 ° C for PA12 may be employed.

In a further variant, the process according to the invention is carried out in a so-called single-screw extruder for the purpose of polymerisation, if desired with a plasticizer which does not hinder the polymerisation. For this purpose, so-called multi-section screws (mult), preferably of suitable section design
i-zone screws, or so-called barrier screws, eg Maillefer company, Ecublen
s) those derived from (CH) are preferably used.

When a single-screw extruder is used, a pump, preferably a gear pump, is preferably used for the purpose of adding the lactam melt and forcing its transportation. Optionally with a plasticizer and further additives,
The continuous addition of the liquid system is preferably done just before entering the extruder.

Shaped polylactam bodies that can be produced by this method are also included in the present invention. The method of the invention is described in more detail in the following examples. However, the scope of the present invention is not limited to this in any case.

[0055]

EXAMPLES Examples 1-3 To prepare a liquid system, be sure to use a protective gas atmosphere (protecti
It is necessary to work in a ve gas atmosphere).
Put component a) in a container equipped with an internal temperature measuring device and heat up to 60-80 ° C. Then, component c) is added with stirring and mixed homogeneously. After forming a clear solution,
Component b) and, if desired, additive d) are added while controlling the temperature not to exceed 90 ° C. The resulting solution is a liquid at room temperature and is stable on storage. They do not form crusts or sludges, even in dry air.

[0056]

[Table 1]

DMPU: N-N'-dimethylpropylene, BASF Ludwshafen
igshafen) (FRG) Na-CL: sodium caprolactamate, percast (Pacast AG), Sargans (CH) Bis-Ox: lysinyl-bisoxazoline, Loxamid 8523 ^(R) , Henkel KG, Dusseldorf (FRG) CL-MDI: Methylenebisphenyl isocyanate blocked with caprolactam, Grill Bond (Gril
bond) IL6 ^(R) , Ems-Chemie A
G), Domat / Ems (CH), CD: Bis- (2,6-diisopropylphenyl) -carbodiimide, Stabilisator 70
00 ^(R) , Raschig AG, Ludwigshafen (FRG) NMP: N-methyl-2-pyrrolidone CL: Caprolactam

Examples 4-6 The following procedure is used to test a liquid system suitable for initiating active anionic lactam polymerization: Place the lactam melt in a glass container under a nitrogen atmosphere and stir the liquid. The system is added at 170 ° C. where polymerization is initiated.
After measuring the time when the stirrer was removed,
Polymerization was carried out at 70 ° C. for 1 hour.

[0059]

[Table 2]

T: Time until the melt cannot be stirred

Examples 7 to 21 Further liquid systems were prepared in the same manner as in Examples 1 to 3. Table 3 shows their compositions. The data for the run and the results of the active anionic lactam polymerization with the addition of the liquid system are summarized in Table 4. The procedure is in Examples 4-6.
Is the same as When the melt could no longer be stirred, the polymerization was continued for 60 minutes at the above-mentioned polymerization temperature, after which the viscosity of the solution and the melting point of the polymer were measured. The extractable residual content in all polymers was clearly below 1% by weight. Comparison of various times t _u showed that the composition of the liquid system can influence the polymerization rate and thereby control the polymerization.

[0062]

[Table 3]

CL: caprolactam LL: laurinlactam NMP: N-methyl-2-pyrrolidone, BASF
F), Ludwigshafen (FRG) NOP: N-octyl-2-pyrrolidone, PCD: polycarbodiimide stavaxol (Stabax
ol) P ^(R) , Rhein Chemie Gmb
H, Mannheim (FRG), DOS: dioctyl sebacate, Edenol
888 ^(R) , Henkel, Düsseldorf (FR
G), PA: Phenolic antioxidant, Irganox 1135
^(R) , Shiva-Geigy, Basel (CH) *) Component d) further comprises about 70% by weight of component b) (lactam ratio) DMPU: N-N'-dimethyl propylene urea, Basuf (BASF) Ludwigs Hafen (Ludwigshafe
n) (FRG) DMI: NN′-Dimethylethyleneurea, Siebner Hegner R
ohstoffe), Zurich (CH), TBH: Tetrabutylurea, Basuf, Ludwigshafen (FRG) TEH: Tetraethylurea, Fluka AG,
Buchs (CH) TMH: Tetramethylurea, Fluka AG,
Buchs (CH) Na-CL: Sodium caprolactamate in caprolactam, sodium lactamate ratio about 30% by weight, Pacast AG, Sargans (C)
H), Na-LL: Sodium laurin lactamate in laurin lactam, laurin lactamate ratio of about 30% by weight, CD: Bis- (2,6-diisopropylphenyl) -carbodiimide, Stabilisator 70
00 ^(R) , Raschig AG, Ludwigshafen (FRG) CL-MDI: methylene diisocyanate blocked with caprolactam, Grilbond IL
6 ^(R) , Ems-Chemie AG, Domato /
Domat / Ems (CH), Bis-Ox: lysinyl-bisoxazoline, Loxamid 8523 ^(R) , Henkel, Dusseldorf (FRG) Rc-Ox: lysinyl-oxazoline, loxamide (Lo)
xamid) 8513 ^(R) , Henkel, Düsseldorf (FRG) DCC: dicyclohexylcarbodiimide, Toyo
Kasei Kogyo, Osaka (J)

[0064]

[Table 4]

T: Polymerization temperature t: Time until the melt cannot be stirred Smp ° C .: DSC melting point of polymer Relative viscosity of polymer: Polymer in m-cresol 0.5
% Nmb: Very high viscosity, not measurable by ordinary method

Example 22 Using liquid system 21, the time t was recorded as a function of the polymerization temperature T for reactions of more than 99% by weight of lactam (less than 1% by weight of extractables).

[0067]

[Table 5]

In a further test, minerals, dye pigments, defoamers and stabilizers were added to the lactam.
Liquid system 3 from Example 21 and then added to 12 melts
Polymerization was carried out at 220 ° C. with the addition of wt%. Well dried powder form Mg (OH) ₂ , Ca (OH) ₂ , kaolin (ka
olin), micro-talc and CaCO ₃ were added and the melt was polymerized at 220 ° C. for 20 minutes. As a result, a polymer having a relative solution viscosity of 2.0 to 2.5 was obtained. Antioxidants such as Tinuvin 770 ^(R) from Ciba-Geigy, Irganox
If 245 ^(R) and Irgafos 168 ^(R) are used, and these additives have active H-atoms that are not sufficiently sterically shielded, the concentration of these stabilizers is 0.5.
It was shown that the weight percent should not be exceeded. With respect to defoamers and mold release agents, obviously proportional amounts of less than 1% by weight are used. Bruggemann company, Heibronn of 0.05% by weight
Release agent Bruggolen P derived from (FRG)
12 ^(R) was sufficient for complete removal of the build element from the mold.

Continuous Tests on Twin Screw Extruders The above tests have shown that the polymerization pathway can be significantly affected by compositional changes in the liquid system and temperature control. In this way, increasing the melting temperature can significantly accelerate the polymerization of lactam 12 without increasing the extractable content, which is the lactam-
This is in contrast to the known effect of case 6. In order to record the unique suitability of the process of the invention, a continuously proceeding polymerization process was run on a synchronously operating twin screw extruder, Werner
Werner und Pflei
derer company), Stuttgart (FR)
Performed using ZSK30 with an I / d ratio of 32 from G). The liquid system at this time is shown in Table 6 below.

[0070]

[Table 6]

In this case, components a), b) and c) correspond to the known products of Table 3. EW3005
Means Edenol W3005, which is an ester plasticizer derived from Henkel, Dusseldorf (FRG). Tests 22, 23, 24 gave stable liquid systems, which were very well suited to initiate the polymerization of lactam-12. In test 24, component d) is used for plasticization, the liquid system of which makes it necessary to add it in high concentrations. In the method of continuous extruder polymerization, the lactam was melted in the inlet region of the extruder and then the liquid system was continuously injected into the lactam melt in a defined weight ratio with vigorous mixing. These test data are summarized in Table 7.

[0072]

[Table 7]

1) Extractable inclusions also include the plasticizer from system 24, EW3005.

These are some examples of test configurations and are the results of numerous tests performed. In all cases, uniform extruded strands were obtained which were easy to pelletize. Tests involving dry minerals and chopped glass and the many deformability of twin-screw extruders have led to numerous processing steps simultaneously with or after the polymerization of lactams, for example mineral and glass fortification, addition of dyes and stabilizers. It has been shown that the addition of flame retardants and tougheners, and all combinations are possible.

The granules from this continuous polymerization process are remeltable and can be processed further, for example after any extraction of residual monomers in the injection molding process. However,
Due to the continuity of the process, it is also possible to use shaping dies directly as dies, which can directly produce, for example, glass-reinforced profiles or plasticized tubes. The obtained product can be subjected to heat treatment and / or secondary molding later.

[0076]

By the continuous polymerization method of the active anion lactam of the present invention, the active anion lactam polymerization can be carried out efficiently and reproducibly, and the polymerization is preferably carried out continuously by a twin screw extruder. It is possible to obtain a uniform quality polylactam of constant quality using a liquid system that simultaneously contains an activator and a catalyst. Also, the reaction of the lactams is rapid and uniform, most of the time after 100-200 seconds, the method can be directly combined with the continuous shaping step, which can reduce the technical expenditure. Furthermore, the thermal stress of the obtained polymer is considerably reduced.

Claims (14)

[Claims] 1. A process of feeding a lactam for anionic lactam polymerization under anhydrous conditions and a catalyst and an activator to a heatable and continuously operating mixing and conveying device, operating temperature while continuously mixing the lactam. Active anion lactam under an inert atmosphere comprising heating to at least partially polymerize, and shaping in a mold or delivering the melt as a strand, rather than cooling and pelletizing. In the continuous polymerization method of, the active anion lactam is characterized in that the addition of the activator and the catalyst to the anhydrous lactam melt is carried out by continuous addition in a liquid system containing both the activator and the catalyst. Polymerization method. 2. The continuous polymerization process according to claim 1, characterized in that the lactam is selected from caprolactam, enantolactam, laurinlactam and mixtures thereof. 3. A continuous polymerization process according to claim 1 or 2, characterized in that the liquid system consists essentially of: a) basic components and a1) at least 1 as solvent.
20 to 80 parts by weight of one N-substituted carboxylic acid amide compound, and / or a2) at least one N, N′-disubstituted urea compound (both of which may include a heterocycle formed by their substitution) B) 5-30 parts by weight of at least one alkali or alkaline earth lactamate as catalyst, c) 5-30 parts by weight of at least one compound activating anionic lactam polymerization [a), b) and c) 10
0 parts by weight or less and optionally the following d) are added] d) Additives and additives depending on processing or use. 4. The continuous polymerization method according to claim 1, wherein 0.5 to 15 parts by weight of the liquid system is added to 100 parts by weight of the lactam melt. 5. A continuous polymerization process according to claim 1, characterized in that additives from the group of additives which depend on processing and use according to the prior art are added. 6. A twin-screw extruder, a coaxial kneader, or a single-screw extruder, which is connected to a conveying pump at an inlet, is used as the mixing and conveying means. The continuous polymerization method described in 1. 7. The melt is at least partially polymerized by matching proportional amounts of liquid system, temperature control and residence time, which is then guided to shaping, whereby intermediate addition of additives and / or degassing occurs. The continuous polymerization method according to any one of claims 1 to 6, wherein steps are selectively incorporated. 8. The lactam melt is at least partially polymerized in the extruder and fully polymerized below the melting point of the polylactam during shaping and / or in successive steps. The continuous polymerization method described in 1. 9. The temperature of the melt rises above the melting point of the polymer in the range of 200-320 ° C.,
The continuous polymerization method according to claim 1. 10. The continuous polymerization method according to claim 1, wherein degassing is carried out under atmospheric pressure or reduced pressure. 11. Molding into a monofilament, tube, plate or profile is carried out,
The continuous polymerization method according to claim 1. 12. The continuous polymerization process according to claim 1, wherein the thermal post-treatment is carried out at a temperature below the melting point of the polylactam, preferably in an inert environment. 13. The continuous polymerization method according to claim 1, wherein the post-treatment is liquid extraction. 14. A shaped polyamide body which can be produced by the continuous polymerization method according to claim 1.